1. Field of the Invention
The present invention relates to a web guide roller for a rotary printing machine, and more particularly to a web guide roller with an automatically cleaning device.
2. Description of the Prior Art
A web guide roller for guiding a web (a printing paper) running through a printing machine during a printing process is contaminated by ink, paper debris and the like as the printing time elapses. When the web guide roller is contaminated, the contamination is transferred to a printing paper surface to decrease the product quality. Accordingly, in a case of a newspaper rotary press, in order to clean the contamination having adhered to the web guide roller after the interruption of the printing work, an operator manually cleans respective web guide rollers with waste cloth impregnated by cleaning oil or the like.
In a printing machine such as a newspaper rotary press each having more than 100 web guide rollers in a single system, it requires considerable labor to clean the respective web guide rollers manually as described above, and it is very dangerous to clean the web guide rollers located at high positions. Depending on the positions of installation of the web guide rollers, it is difficult for the operator to access there or it is difficult to perform the cleaning work because of narrow space within the printing machine.
Now, a conventional guide roller, for example, a conveyor roller, incorporating a motor therein is constructed such that a motor with a reduction unit is provided in a roller body, the outer periphery of a stator of the motor is integrally fixed to the inner wall of the roller body, an output shaft of the reduction unit is concentrically jointed to one of opposite shaft ends of the roller, and the roller body is rotatable with respect to the opposite shaft ends. In this construction, when the motor is energized with the opposite shaft ends of the roller unrotatably fixed, the rotor cannot be rotated and the stator is rotated relatively to the rotor because the rotor shaft of the motor, that is, an output shaft of the reduction unit is unrotatably fixed to side frames. In other words, the roller body can be rotated with respect to the roller shaft.
In the normal method of use, i.e. when the both shafts are fixed to a machine frame, with the aforesaid conventional motor guide roller, it requires an extremely great force to desirably rotate the roller body by applying a force to the outer periphery thereof while the motor is not energized. If such conventional motor guide rollers are employed as the web guide rollers in the rotary printing machine, when the power is cut off, the roller bodies suffer from the problem that the roller bodies cannot be rotated along with the running of the web and it is difficult to clean the web guide rollers manually.